In a basic structure of a prior art transformer, a winding pipe passes through a core, and the winding pipe is divided into two coil areas: a primary coil area and a secondary coil area, and a primary coil and a secondary coil are wound respectively around the two coil areas, and the primary coil area inputs a voltage, and after the core is excited, the voltage at the secondary coil area is converted and outputted for the use by a load.
For example, a liquid crystal display (LCD) requires a high brightness, and some manufacturers increase the number of lamps for a backlit module in an LCD device, and thus increasing the number of transformers. As a result, not only the size of the LCD device becomes larger, but the weight also becomes heavier. Therefore, some manufacturers design a structure of using a single transformer to drive several lamps in order to solve the foregoing problem. In other words, the demand of using a single transformer to support the application of two or more loads becomes higher.
The prior art transformer that supports the application of two or more loads comprises a primary winding rack and at least two secondary winding racks. The secondary winding racks are aligned side by side with each other and connected with the primary winding rack; the primary winding rack comprises a primary winding pipe, and each secondary winding rack comprises a secondary winding pipe, and the primary winding pipe and the secondary winding pipe are installed horizontally. Further, the primary winding pipe and each secondary winding pipe are wound with a primary coil and a secondary coil respectively, and the primary winding pipe and each secondary winding pipe pass through a core. After the voltage inputted from the primary coil area is excited by the core, the voltage is converted and outputted from each secondary coil area for the use of several loads.
It is worth to note that the prior art primary winding pipe and the secondary winding pipe are installed horizontally, so that if the load power is increased (or the number of connected loads is increased), the primary coil of the primary winding pipe results in a significant rise of temperature, and thus creating an overheat problem to the transformer. Although the diameter of the wire of the primary coil can be increased to solve the overheat problem, the thickness of the primary coil winding around the primary winding pipe will be increased in the vertical direction, since the primary winding pipe is installed horizontally. As a result, the thickness of the transformer will be increased, and the volume of the transformer cannot be reduced.
Referring to FIGS. 7 and 8 for the prior art inverter and a discharge lamp light up circuit using the inverter (as disclosed in R.O.C. Patent Publication No. I227097), one inverter is used to obtain a plurality of outputs. A pair of magnetic cores 700 are combined into a closed magnetic path, and a primary coil 800 and a plurality of secondary coils 810 are wound around the magnetic core 700 in any one direction, and then the primary coil 800 and a plurality of secondary coils 810 are wound horizontally on the same plane, so that the primary coil 800 and the secondary coil 810 are wound vertically. Referring to FIG. 9, the two secondary coils 810 are wound in the opposite direction to prevent an electric discharge produced between the magnetic core 700 and the wiring pattern. However, the secondary coil 810 is wound in the same winding and is not isolated by any partition design, and thus it is very easy to come up with a deviated winding by machine, and the potential resisting effect of the inverter is not as good.